Tank-wall temperature indicator



March 12, 1946.

:3 //W//////'//////1I/ /f/////////// l 32 I ll C. H. WALSH TANK-WALL TEMPERATURE INDICATOR Original Filed June 30, 1943 /37 Fig. 2

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Patented Mar. l2, 1946 UNITED STATES PATENT OFFICE Divided and this application August 8, 1944, Serial No. 548,571

(Cl. D-442) 6 Claims.

This invention relates generally to temperature indicators, and in some particular aspects to an indicator for application externally to a container for indicating the attainment by the tank wall of certain predetermined temperatures.

This application is a division of my prior application Serial No. 492,957, led June 30, 1943, in which I have claimed a fusible mechanical releasable semaphoric type of temperature indicator. The claims in the present application are directed to a fusible releasable combination of an electrical contact circuit closed with a mechanical releasable type of temperature indicator.

Among the objects of the present invention may be noted the provision of a housing carrying an upstanding container containing a reciprocably movable member rigidly held in normal position by means of a frozen fusible material within the container, together with means externally of the housing for visibly indicating the occurrence of a reciprocation of the movable member which occurs in response to fusing of the fusible material; the provision of means for guiding the reoiprocations of the the reciprocably movable member; the provision of means for assuring complete reciprocation of the movable member when the fusible material fuses; the provision of electrical contacts to make possible remote as well as local indication of an operation of the device; and in general the provision of a device of the character described in which several functions are performed by certain elements, thereby simplifying the construction. Other objects Will be in part obvious, and in part pointed out hereiii-after.

The invention comprises the elements and cominations thereof, features of construction and arrangement of parts to be exemplified in the description to follow, and the scope of the invention will be speciiically pointed out in the appended claims.

In the drawing: Fig. l is an elevational view of the construction, shown in section; and Fig. 2 is a sectional view of the structure as it appears along Vthe line 2 2 of Fig. l.

Referring in detail to the drawing, a boxflike Vcontainer of insulating material I0, for example, porcelain, open along one side, is provided as a housing for the contained mechanism of the device. A bolt I3, with cooperating nut I4, Vis arranged to pass through an opening in the rear wall of the housing I0, for the purpose of supporting within the housing the U-shaped mech- 'anism support I5, and for the purpose of supporting outside of the housing the U-shaped.

hanger attachment II. The latter is arranged to eng-age some sort of a resilient hanger, partially shown at l2, so that the housing Ill is continuously urged toward the wall 31, the latter representing a portion of a tank wall the temperature of which is to be indicated by the device.

A hollow tubular container I6, preferably of a material having relatively good heat conductivity, such as copper, is fitted between the arms of the U-shaped mechanism support I5 adjacent to the ends thereof, being rigidly secured thereto by soldering, bra-zing, or other suitable means, and arranged so that one side of the tubular oontainer IG projects slightly from the housing I0 to assure contact of the container with the tank wall 3?. The hollow of the container I6 is closed at the lower end and open at the upper end, and the reciprocably movable member II is tted loosely into the hollow, extending downwardly therein through the open and upper end. In the normal position, the reciprocable member I1 is rigidly joined to the container I6 by means of the frozen fusible material I8, which is disposed within the annular space between these members. The particular fusible material to be used should be selected with reference to the desired melting point; for example, it may be Woods metal or other eutectic alloy, or it may be some organic rmaterial having suitable characteristics,

Within the housing I9, and extending laterally across the support I5, the rotatable shaft 24 is journalled, and the U-shaped latch member 2l rigidly secured thereto, conveniently as a drive fit, centrally Within the space between the arms of the U-shaped mechanism support I5. A portion of the shaft 24 extends to a point outside of the housing I0, and to this portion is fastened, by means of the drive pin 38, the semaphore 36, the latter extending upwardly and outwardly when the shaft 24 is in the normal position, thereby continuously biasing the shaft 24 toward rotation in clockwise direction as viewed in Fig. 1.

A push rod I9 and a pull rod 20 are rigidly fastened at their respective upper ends to an out- `wardly extended portion of the container closure 21, for reciprocable movement with the reciprooably movable member I'I. The guide block 25 is rigidly clamped between the spaced arms of the -rnechanism support I5 by means of the rivet 26, and the rods I9 and 20 extend downwardly in substantially parallel spaced relationship to points at opposite sides of the shaft 24 through vertically extending spaced openings in the guide block, thereby continuouslymaintaining the lower ends of the rods in the desired position, and restraining any rotary movement of the reciprocable member about its vertical axis.

When the fusible material I8 is frozen and the reciprocable member I1 rigidly fastened to the container I 6 through frictional engagement of the latter members with the frozen fusible material, rotary movement of the semaphore 36 from the normal position is restrained by the engagement of the bar 22 with the lower end of the push rod I9, the bar 22 extending laterally and horizontally across the latch member 2l, and being rigidly fastened thereto in any suitable manner, such as soldering. The above-described position of the elements is herein regarded as the normal position.

When the elements are in the normal position, the lower and hooked end portion of the pull rod 2l) is positioned in the path of movement of and spaced from the laterally extending pin 23, which provides the pull rod engaging portion of the latch member 2l.

At the lower end of the insulating housing H3, an electrical contact 38, formed from a strip of upwardly and inwardly extending resilient conducting material, is rigidly secured to the housing II) by means of the terminal bolt 3| and cooperating nut 32, the latter elements clamping a portion of the contact 3D against the bottom inner surface, and a portion of the terminal 33 against the bottom outer surface, of the housing Ill, The terminal 33 is provided with a terminal connector 34 to electrically connect thereto a conductor 35.

A movable contact portion 29 of the latch member 2| is provided at the outwardly extended porf tion of the latter, and the relatively fixed normally insulated contact is positioned in' the path of movement of the contact 28 which attends rotary movement of the shaft 24 from the normal position.

Upon attainment by the tank wall 31 of a temperature which causes fusing of the normally frozen fusible material I8, the biasing means urging the shaft 24 toward rotation lifts the push rod engaging portion 22 of the latch member 2l, thus urging upwardly the assembly including the reciprocable member II and the rods I 9 and 2U. Before the downwardly moving pull rod engaging portion 23 of the latch member 2l contacts the hooked end portion of the pull rod 2l), the bar 22 moves out from under the push rodi 9, leaving the reciprocable member l'! free to move back to the normal and original position. Following the release of the push rod I9, the latch member portion 23 strikes the pull rod 2li, and thereby urges the reciprocable member I1 back to the normal position, concurrently, the movable contact 29 moves around to engagement with the cooperating contact 30, for the purpose of completing an external circuit, not shown, and thereby ringing a bell, lighting a lamp, or actuating some cooling mechanism. It may be noted that the electrical contacts are arranged to close a circuit from the insulated terminal 33 to the normally grounded member I2, and the connection of apparatus for actuation by closing of the contacts is believed so apparent as to require no detailed description. The dashed lines of Fig. 1 indicate the position of the contact 29, along with that of the pull rod engaging portion 23 of the latch member 2|, following the fusing of the fusible material I8.

The portion of the push rod I9 below the guide block 25 is formed from resilient material, and

is transiently deflected by engagement with the bar 22 as the shaft 24 is rotated to reset, subsequently springing back to the normal position and again so holding the elements if the fusible material is frozen.

It may be noted that the organization herein described is one in which the energy available for pulling the reciprocably movable member Il back to the normal position is greater than the energy available for pushing the member I'I to the position to cause operation of the device, since the pull rod engaging portion of the latch member engages the pull rod at a time when the parts have acquired momentum, and in addition, are farther over center. This construction asy sures proper resetting of the device, and effectively prevents sticking of the reciprocable mem ber Il at a point where the device cannot be re latched in the normal position upon the freezing of the fusible material I8. In addition, the construction also assures that the closure 21 of the tubular container will return to the position in which the container is closed, to prevent entrance of foreign material therein or egress of the fusible material therefrom.

The foregoing description is intended as illus-v trative rather than limiting, for obvious modifications will occur to a person skilled in the art.

I claim as my invention:

l. A tank-wall temperature indicating device comprising a housing having mounted therein a hollowT container closed at the lower end and open at the upper end, a reciprocably movable member fitted loosely into the hollow of said container and arranged for endwise movement with respect thereto, normally frozen fusible material disposed within the space between said container and said movable member and normally joining said member to said container to restrain said endwise movement, a Vrotatable shaft journalled within said housing, a latch member fastened to said shaft, a movable contact carried by said latch member, a normally insulated fixed contact arranged to cooperate therewith, said fixed Contact being mounted on said housing and normally spaced from said movable contact in the path of movement thereof, means biasing said shaft for rotary movement, connecting means secured to said movable member and arranged to operatively connect said latch member to said movable member for normally restraining rotary movement of said shaft and to disconnect said latch member from said movable member in ree sponse to a predetermined upward and endwise movement of said movable member to permit concurrent rotary movement of said shaft and endwise movement downwardly of said movable member to the normal position.

2. A tank-wall temperature indicating device comprising a housing having mounted therein a holow container closed at the lower end and open at the upper end, a reciprocably movable member tted loosely into the hollow of said container and arranged for endwise movement with respect thereto, normally frozen fusible material disposed within the space between said container and said movable member and normally joining said member to said container to restrain said 4endwise movement, a rotatable shaft journalled within asid housing, a latch member fastened to said shaft, a, movable Contact movable with said shaft, a normally insulated relatively fixed contact arranged to cooperate therewith, said fixed contact being mounted on said housing and norn mally spaced from said movable contact in the path of movement thereof, means biasing said shaft for rotary movement, connecting means secured to said movable member and arranged to operatively connect said latch member to said movable member for normally restraining rotary movement of said shaft and to disconnect said latch member from said movable member in response to a predetermined endwise movement of said movable member to permit concurrent rotary movement of said shaft and endwise movement downwardly of said movable member to the normal position, and indicating means actuated by the rotary movement of said shaft for visibly indicating externally of said housing the occurrence of the concurrent movements.

3. A tank-wall temperature indicating device comprising a housing having mounted therein a hollow container closed at the lower end and open at the upper end, a reciprocably movable member extending loosely into the hollow of said container to a normal position and arranged for endwise movement with respect thereto, normally frozen fusible material disposed within the space between said container and said movable member and normally joining said member to said container to restrain said endwise movement, a rotatable shaft in said housing, a latch member fastened to said shaft, a movable contact movable with said shaft, a normally insulated relatively fixed contact arranged to cooperate therewith, said fixed contact being mounted on said housing and normally spaced from said movable contact in the path of movement thereof, means biasing said shaft for rotary movement, connecting means secured to said movable member and arranged to releasably engage said latch member while normally urging said movable member up- Ward, said connecting means disengaging said latch member from said movable member in response to a predetermined upward movement thereof to concurrently release said shaft for rotary movement and said movable member for downward endwise movement to the normal position.

4. A tank-wall temperature indicating device comprising a housing having mounted therein a hollow container closed at the lower end and open at the upper end, a reciprocably movable member extending loosely into the hollow of said container to a normal position and arranged for endwise movement with respect thereto, normally frozen fusible material disposed within the space between said container and said movable member and normally joining said member to said container to restrain said endwise movement, a rotatable shaft in said housing, a latch member fastened to said shaft, a contact movable with said shaft, a normally insulated relatively fixed contact arranged to cooperate therewith, said fixed contact being mounted on said housing and normally spaced from the movable contact in the path of movement thereof, means biasing said shaft for rotary movement, connecting means secured to said movable member and arranged to releasably engage said latch member while normally urging said movable member upward, said connecting means disengaging said latch member from said movable member in response to a predetermined upward movement thereof to concurrently release said shaft for rotary movement and said movable member for downward endwise movement to the normal position, guide means secured to said container continuously restraining rotary movement of said reciprocably movable member with respect to said container, and indicating means operative when said shaft rotates for visibly indicating externally of said housing the occurrence of the concurrent movements.

5. A temperature indicator comprising a housing, a container having a longitudinally extending hollow therein closed at the lower end and open at the upper end, a longitudinally reciprocable member fitted loosely into said hollow and extending downwardly therein through the open end of said container to a normal position, normally frozen fusible material disposed within said hollow and normally rigidly fastening said reciprocable member to said container, biasing means effective to move said reciprocable member upwardly in endwise direction when said fusible material fuses, means dependent upon the upward movement of said reciprocable member to disconnect said biasing means therefrom to permit said reciprocable member to drop back to the normal position following the occurrence of said upward movement, means effective following the disconnection for reconnecting said biasing means to said reciprocable member to urge said reciprocable member back to the normal position, and normally insulated relatively movable contacts supported within said housing and operable to close upon the occurrence of a reciprocation of said reciprocably movable member.

6. A tank-wall temperature indicating device comprising a housing of insulating material having mounted therein a hollow container closed at the lower end and open at the upper end, a reciprocably movable member fitted loosely into the hollow of said container and arranged for endwise movement with respect thereto, normally frozen fusible material disposed within the space between said container and said movable member and normally joining said member to said container to restrain said endwise movement, a rotatable shaft in said housing, a latch member fastened to said shaft, a contact movable with said shaft, a normally insulated relatively fixed contact arranged to cooperate therewith, said fixed contact being mounted on said housing and normally spaced from the movable contact in the path of movement of the latter. means biasing said shaft for rotary movement, connecting means secured to said movable member and arranged to operatively connect said latch member to said movable member for normally restraining rotary movement of said shaft and to disconnect'l said latch member from said movable member in response to a predetermined endwise movement of said movable member to permit concurrent rotary movement of said shaft and endwise movement downwardly of said movable member to the normal position, additional means responsive to said rotary movement for operatively reconnecting said movable member with said latch member to assist said endwise movement downwardly, andindicating means operative when said shaft rotates for visibly indicating externally of said housing the occurrence of the concurrent movements.

CARROLL H. WALSH. 

